Perpendicular infusion set and disposable inserter

ABSTRACT

An infusion set is disclosed that includes an inserter including an inserter housing having at least one flexible arm for holding an infusion set in a single axial position prior to insertion of at least a portion of a cannula of the infusion set, the inserter housing having a surface for contacting the patient&#39;s skin. The inserter also includes a movable plunger disposed within the inserter housing for releasing the infusion set from the inserter housing, impacting the infusion set, and imparting momentum to the infusion set to insert the cannula into the patient&#39;s skin. The inserter additionally includes a biasing element biasing the plunger toward the activated position.

RELATED APPLICATION

This application is a division of U.S. patent application Ser. No.13/629,575, filed Sep. 27, 2017, which is incorporated by referenceherein in its entirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a medical insertion device assembly,and more particularly, to an intradermal infusion set and an insertertherefor.

2. Description of the Related Art

A large number of people, including those suffering from conditions suchas diabetes use some form of infusion therapy, such as daily insulininfusions to maintain close control of their glucose levels. There aretwo principal modes of daily insulin therapy. The first mode includessyringes and insulin pens. These devices are simple to use and arerelatively low in cost, but they require a needle stick at eachinjection, typically three to four times per day. The second modeincludes infusion pump therapy, which entails the purchase of an insulinpump that lasts for about three years. The initial cost of the pump canbe significant, but from a user perspective, the overwhelming majorityof patients who have used pumps prefer to remain with pumps for the restof their lives. This is because infusion pumps, although more complexthan syringes and pens, offer the advantages of continuous infusion ofinsulin, precision dosing and programmable delivery schedules. Thisresults in closer blood glucose control and an improved feeling ofwellness.

The use of an infusion pump requires the use of a disposable component,typically referred to as an infusion set or pump set, which conveys theinsulin from a reservoir within the pump into the skin of the patient.An infusion set typically consists of a pump connector, a length oftubing, and a hub or base from which an infusion needle or cannulaextends. The hub or base has an adhesive which retains the base on theskin surface during use, which may be applied to the skin manually orwith the aid of a manual or automatic insertion device.

Currently, most insulin infusion sets deliver insulin to thesubcutaneous layers of skin using either fixed metal needles or flexibleplastic cannulas. Such infusion sets typically deliver insulin 4-10 mmbelow the skin surface. However, the upper 3 mm of skin surface, theintradermal space, facilitates better drug absorption. Unfortunately,due to the relative thinness of the intradermal layer, inserting aneedle at such depth and maintaining an infusion site over an extendedperiod of time within this narrow band is difficult.

Further, most insulin infusion sets typically do not provide anyfeatures to isolate the inserted needle or cannula from shock or otherexternal forces. Since these infusion sets typically deliver insulin4-10 mm below the skin surface, shock or other external forces to theset have less effect on the deeper inserted needle or cannula. But wherean attempt is made to target the upper 3 mm of skin surface, any shockor movement of the set can adversely affect needle insertion andinfusion performance.

Still further, most insulin infusion sets use inserters that can resultin skin surface “tenting” during needle insertion, where the skinsurface is deflected somewhat prior to or during needle insertion whichmakes precisely targeting the upper 3 mm of skin surface difficult.Moreover, with many inserters, after insertion of the infusion set, theuser must take the additional step of removing or separating theinserter from the infusion device. This action can displace the insertedinfusion set even if there is an adhesive on the bottom of the infusionset.

Accordingly, a need exists for an infusion set that can deliver contentto the upper 3 mm of skin surface, the intradermal space, to facilitatebetter drug absorption, while maintaining a degree of comfort to theuser. Further, it is desirable to avoid infusion set displacement afterinsertion, particularly for intradermal infusion sets having shortinfusion needles.

SUMMARY OF EMBODIMENTS OF THE INVENTION

Accordingly, it is an aspect of the present invention to provide aninfusion set and an inserter that can insert the infusion set to delivercontent to the intradermal space, to facilitate better drug absorption,while maintaining a degree of comfort to the user. It is another aspectof the invention to provide an inserter that avoids infusion setdisplacement after insertion.

The foregoing and/or other aspects of the present invention are achievedby providing an infusion set inserter including an inserter housinghaving at least one flexible arm for holding an infusion set in a singleaxial position prior to insertion of at least a portion of a cannula ofthe infusion set, the inserter housing having a surface for contactingthe patient's skin. The inserter also includes a movable plungerdisposed within the inserter housing for releasing the infusion set fromthe inserter housing, impacting the infusion set, and imparting momentumto the infusion set to insert the cannula into the patient's skin. Theinserter additionally includes a biasing element biasing the plungertoward the activated position.

The foregoing and/or other aspects of the present invention are alsoachieved by providing an infusion set inserter including an inserterhousing for holding an infusion set in a single axial position prior toinsertion of at least a portion of a cannula of the infusion set, theinserter housing having a surface for contacting the patient's skin. Theinserter also includes a movable plunger disposed within the inserterhousing for releasing the infusion set from the inserter housing,impacting the infusion set, and imparting momentum to the infusion setto insert the cannula into the patient's skin. The plunger includes acantilevered arm with a hook disposed at a free end thereof forcontacting the inserter housing to selectively retain the plunger in apre-activated position prior to activation. The inserter additionallyincludes a biasing element biasing the plunger toward the activatedposition.

The foregoing and/or other aspects of the present invention are alsoachieved by providing a method of inserting at least a portion of acannula of an infusion set into a patient's skin. The method includesmaintaining the infusion set in a single axial position in an inserterhousing using a at least one flexible arm of the inserter housing, andplacing the inserter housing on the patient's skin over an intendedinfusion site. The method also includes releasing a biased plunger tomove within the inserter. Movement of the plunger releases the infusionset from the inserter housing, impacts the infusion set, and impartsmomentum to the infusion set to insert the cannula into the patient'sskin.

The foregoing and/or other aspects of the present invention are alsoachieved by providing an insertion device assembly including an infusionset and an infusion set inserter. The infusion set includes a base witha port disposed on a first side thereof and a cannula disposed on anopposing, second side thereof, the second side having at least onedetent recessed from the surface thereof. The inserter includes aninserter housing for holding the infusion set, the inserter housingincluding a surface for contacting the patient's skin and at least onearm for selectively engaging the detent in the infusion set base tomaintain the infusion set within the inserter housing, a movable plungerdisposed within the inserter housing, and a biasing element biasing theplunger toward a patient end of the inserter housing.

The foregoing and/or other aspects of the present invention are alsoachieved by providing an infusion set that includes a base, aself-sealing septum, and a fluid connector for connection with anexternal pump, the fluid connector being lockable to the base. The baseincludes a first side, an opposing, second side for contacting apatient's skin, a base cannula extending from the second side in asecond direction for insertion into the patient's skin, an engagingprotrusion extending in the first direction from the first side of thebase, and a locking structure that one of extends in the first directionfrom the top side of the base or is recessed from the first side of thebase. The self-sealing septum is disposed within a fluid path betweenthe port and the cannula.

The fluid connector includes a connector cannula for insertion throughthe port and the septum when the fluid connector is connected with thebase, and a first connector for rotatably engaging the engagingprotrusion to prevent displacement of the fluid connector in the firstdirection relative to the base and prevent rotation of the fluidconnector in a single, first rotational direction relative to the base.The fluid connector also includes a second connector for engaging thelocking structure to prevent rotation of the fluid connector in a secondrotational direction opposite to the first rotational direction butpermit displacement of the fluid connector in the first directionrelative to the base.

Additional and/or other aspects and advantages of the present inventionwill be set forth in the description that follows, or will be apparentfrom the description, or may be learned by practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other aspects and advantages of embodiments of theinvention will become apparent and more readily appreciated from thefollowing detailed description, taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a perspective view of an insertion device assembly inaccordance with an embodiment of the present invention;

FIG. 2 is an exploded view of the assembly of FIG. 1;

FIG. 3 is a perspective view of a plunger of the assembly of FIG. 1;

FIG. 4 is a cross-sectional view of the plunger of FIG. 3;

FIG. 5 is a perspective view of a bottom of the plunger of FIG. 3;

FIG. 6 is a perspective view of an inserter base of the assembly of FIG.1;

FIG. 7 is a cross-sectional view of the assembly of FIG. 1 taken alongline 7-7 of FIG. 1;

FIG. 8 is a perspective view of a cap being removed from the assembly ofFIG. 1;

FIGS. 9 and 10 are cross-sectional views of the assembly of FIG. 1respectively taken along lines 7-7 and 10-10 of FIG. 1, and illustratethe plunger of FIG. 3 in a pre-activated position;

FIG. 11 is a cross-sectional view illustrating the plunger of FIG. 3 inan activated position;

FIG. 12 is a perspective view of an infusion set of the assembly of FIG.1;

FIG. 13 is a perspective view of the bottom of a fluid connector of theinfusion set of FIG. 12;

FIG. 14 is a perspective view of a base of the infusion set of FIG. 12;

FIG. 15 is a cross-sectional view of the infusion set of FIG. 12 takenalong the line 15-15 of FIG. 12;

FIG. 16 is a cross-sectional view of the infusion set of FIG. 12 takenalong the line 16-16 of FIG. 12;

FIG. 17 is a cross-sectional view of the base of FIG. 14;

FIG. 18 is a perspective view of the bottom of the base of FIG. 14;

FIG. 19 is a perspective view of a base for an infusion set inaccordance with another embodiment of the present invention;

FIG. 20 is a perspective view of an insertion device assembly inaccordance with another embodiment of the present invention;

FIG. 21 is a cross-sectional view of the assembly of FIG. 20;

FIGS. 22 and 23 are, respectively, top and bottom perspective views ofan inserter cap of the assembly of FIG. 20;

FIGS. 24-27 are perspective views of a plunger of the assembly of FIG.20;

FIGS. 28-31 are perspective views of an inserter base of the assembly ofFIG. 20;

FIGS. 32 and 33 are perspective views of the plunger and inserter baseof the assembly of FIG. 20 illustrating their operation;

FIG. 34 is an exploded view of an insertion device assembly inaccordance with another embodiment of the present invention;

FIG. 35 is a cross-sectional view of the assembly of FIG. 34 subsequentto activation;

and

FIG. 36 is a perspective view of the assembly of FIG. 1 with a cannulaguard tray in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE PRESENT INVENTION

Reference will now be made in detail to embodiments of the presentinvention, which are illustrated in the accompanying drawings, whereinlike reference numerals refer to like elements throughout. Theembodiments described herein exemplify, but do not limit, the presentinvention by referring to the drawings. As will be understood by oneskilled in the art, terms such as up, down, bottom, and top arerelative, and are employed to aid illustration, but are not limiting.

FIGS. 1 and 2 illustrate an insertion device assembly 100 in accordancewith an embodiment of the present invention. As shown in FIGS. 1 and 2,the insertion device assembly includes an infusion set inserter 102 andan infusion set 124, which, according to one embodiment, areadvantageously sold as a unit (i.e., with the infusion set 124pre-installed in the inserter 102). The infusion set inserter 102 orinserter 102 includes an inserter cover 104, an inserter cap 108, abiasing member 112, such as a spring 112, an inserter base 116, and aplunger 120. As will be described in greater detail below, the infusionset 124 includes a fluid connector 128 and an infusion set base 132 orbase 132. According to one embodiment, the infusion set 124 alsoincludes tubing 136 for connecting the infusion set 124 with a pump.

Preferably, the inserter cover 104, the inserter cap 108, the inserterbase 116, the plunger 132, the fluid connector 128, and the base 132 aremade of injection-molded plastic. For example, the inserter cover 104,the fluid connector 128, and the base 132 are preferably made ofpolyethylene terephtalate glycol-modified (PETG), and the inserter cap108 and the inserter base 116 are made of acrylonitrile butadienestyrene (ABS). Additionally, the plunger is preferably made of acetal.Further, the biasing member 112 is preferably a metal coil spring. Inaddition, an intradermal cannula or patient needle 292 (see, forexample, FIGS. 7 and 17) that extends approximately 1.5 mm from thelowest surface of the base 132 is preferably a 34 gauge needle 292 madeof stainless steel. The patient needle 292 is hollow and communicateswith the tubing 136 (shown, for example, in FIG. 1).

The inserter cap 108 is secured to the inserter base 116, and together,they form an inserter housing 118. As shown in FIG. 1, the inserterhousing 118 includes a case tube opening 140 to accommodate the tubing136 both prior to and subsequent to activation of the inserter 102.

FIGS. 3-5 illustrate the plunger 120 in greater detail. The plunger 120includes a spring receiving portion 144 for accommodating one end of thespring 112. The spring receiving portion 144 has a central protrusion148 for securing the end of the spring 112. The plunger 120 alsoincludes a pair of cantilevered plunger arms 152 that respectively haveplunger hooks 156 on the unsupported ends thereof. Additionally, theplunger 120 includes a collar or ring structure 160 connected to thespring receiving portion 144 by a plurality of legs 164. The ringstructure 160 and the legs 164 include a tubing opening 168 toaccommodate the tubing 136. A hammer portion 172 for impacting orstriking the infusion set 124 is disposed on the bottom of the springreceiving portion 144. The hammer portion 172 also has a tubing opening176 to accommodate the tubing 136.

As shown in FIG. 6, the inserter base 116 includes a flange 180 and anouter wall 184. The bottom or distal side of the flange 180 has asurface for contacting the skin of the patient. The inserter base 116also includes a plurality of flexible cantilevered arms on the interiorthereof. According to one embodiment, there are two varieties of thesecantilevered arms: those having feet and those without. As will bediscussed in greater detail below, the arms 188 with feet 192 can becharacterized as active arms 188, and the arms 196 without feet can becharacterized as passive arms 196. Also discussed in greater detailbelow, the passive arms 196 include plunger stops 200.

As shown in FIG. 7, the inserter cover 104 includes a pair of safetystructures 204 that prevent inward radial displacement of the plungerarms 152, and therefore prevent accidental activation of the inserter102. According to one embodiment, shown in dotted line in FIG. 7, theinserter cover 104 extends all the way to the bottom more distal end ofthe inserter 102. Additionally, according to one embodiment, theassembly 100 includes a user-removable membrane 208 to maintain thesterility of the interior the assembly 100. The membrane 208 can have atab 215 to aid user removal of the membrane 208, and, according to oneembodiment, can cover the case tubing opening 140. According to oneembodiment, removal of the membrane 208 also removes a backing to anadhesive pad on the bottom of the infusion set 124.

Subsequent to removal of the membrane 208, as shown in FIG. 8, removalof the inserter cover 104 exposes cantilevered activation arms 212 ofthe inserter cap 108. The activation arms 212 include activationprotrusions 216 at the unsupported ends thereof. Additionally, like theplunger 120, the inserter cover 104 includes a central protrusion 220 toaccommodate the spring 112, which is shown more clearly in FIGS. 9 and10.

FIGS. 9 and 10 are cross-sectional views respectively taken along lines7-7 and 10-10 of FIG. 1, and illustrate the inserter 102 in apre-activated state, in which the plunger 120 is in a pre-activatedposition. In the pre-activated position, the ring structure 160 contactsthe cantilevered arms 188 and pulls them radially inward, therebybiasing the arms 188 toward the infusion set 124. As described ingreater detail below, with the plunger 120 in the pre-activatedposition, the feet 192 of the arms 188 engage detents in the bottom ordistal surface of the infusion set 124. In combination with the contactbetween the arms 196 and the infusion set 124, this contact preventsmovement the infusion set 124 within the inserter 102 prior toactivation. In other words, the arms 188 and 196 hold the infusion set124 in a single axial position relative to the inserter housing 118.According to one embodiment, in this position, the infusion set 124 isspaced apart from the patient's skin. According to another embodiment,the distal end of the cannula can be in contact with the patient's skin.

According to one embodiment, in the pre-activated position, the ringstructure 160 also pulls the arms 196 radially inward, but to a lesserdegree than the arms 188. Further, as shown in FIG. 9, in thepre-activated position, the hooks 156 of the plunger arms 152 engageplunger-retaining structures 224 of the inserter cap 108.

Although it is not necessary for the patient to be the one who activatesthe inserter 102, for brevity and clarity, it will be assumedhereinafter that the patient is acting alone. To activate the device,the patient squeezes the activation arms 212 so that the activationprotrusions 216 disengage the plunger hooks 156 from theplunger-retaining structures 224. Then, under the force of the spring112, the plunger 120 travels from the pre-activated position to anactivated position, which is illustrated in FIG. 11.

As the plunger 120 travels from the pre-activated position to theactivated position, the ring structure 160 disengages from thecantilevered arms 188 and 196, thereby permitting the arms 188 to returnto their unbiased position in which the feet 192 no longer engage thedetents in the bottom of the infusion set 124. Once the ring structure160 disengages from the cantilevered arms 188 and 196, the arms 196still compressively engage the sides of the infusion set 124.Subsequently, the hammer portion 172 impacts or strikes the infusion set124, driving the infusion set out of contact with the arms 196 and intothe patient's skin. In other words, this collision between the plunger120 and the infusion set 124 releases the infusion set 124 from theinserter 102 and imparts momentum to the infusion set 124 to insert thecannula or patient needle 292 of the infusion set 124 into the patient'sskin.

According to one embodiment, after the impact, the infusion set 124moves free of the inserter 102 and the plunger 120 under the momentumimparted by the plunger 120. Put another way, the plunger 120 does notcontact the infusion set 124 during insertion of the patient needle 292.According to one embodiment, however, the hammer portion 172 can contactthe infusion set 124 again after insertion. According to yet anotherembodiment, the plunger 120 strikes the infusion set 124, remains incontact with the infusion set 124, and drives the infusion set 124 toinsert the patient needle 292.

As shown in FIG. 11, in the activated position, the plunger stops 200engage the plunger hooks 156 to retain the plunger 120 within theinserter housing 118.

According to one embodiment, disengagement of the ring structure fromthe arms 188 does not disengage the feet 192 from the detents in thebottom of the infusion set 124. In other words, in the unbiasedpositions of the arms 188, the feet 192 remain engaged with the detents.In this embodiment, the impact of the hammer portion 172 disengages theinfusion set from the feet 192 and arms 188. Additionally, according toone embodiment, all of the cantilevered arms 188 and 196 have feet 192.

According to another embodiment, referring to FIGS. 9-11, rather thanpulling the arms 188 or 196 radially inward, in the pre-activatedposition, the ring structure 160 prevents the arms 188 and 196 fromdisplacing radially outward. Then, after moving from the pre-activatedposition to the activated position, the ring structure 160 no longerprevents the arms 188 and 196 from displacing radially outward. Theimpact of the plunger 120 releases the infusion set 124 from the arms188 and 192 and imparts momentum to insert the cannula 292 into thepatient's skin.

According to one embodiment, the inserter 102 is a single-use device,with the infusion set 124 being pre-packaged within the inserter 102.According to another embodiment, although the infusion set 124 can bepre-packaged within the inserter 102, the inserter 102 can be reused.Alternatively, the reusable inserter 102 can be separate from theinfusion set 124. In this reusable embodiment, to move the plunger 120to the pre-activated position, the inserter cover 104 is removed, thusenabling the plunger arms 152 to move radially to engage the plungerhooks 156 with the plunger retaining structures 224. According to oneembodiment (not shown), the plunger 120 includes a handle protrudingthrough the inserter cap 108 to aid the patient in moving the plunger120 to the pre-activated position. According to another embodiment, thepatient presses the plunger 120 upward to move it to the pre-activatedposition. In one embodiment, the patient loads the infusion set 124 intothe inserter 102 prior to moving the plunger 120 to the pre-activatedposition. According to an alternative embodiment, the patient loads theinfusion set 124 into the inserter 102 subsequent to moving the plunger120 to the pre-activated position.

Although the illustrated embodiments depict the infusion set 124, itwill be understood by one skilled in the art that other infusion setscan be used with the inserter 102 without departing from the scope ofthe present invention.

As shown in FIGS. 12-18, the infusion set 124 includes a fluid connector128, a base 132, and an adhesive pad 228. As will be discussed ingreater detail below, to remove the fluid connector 128 from the base132, the fluid connector 128 includes a pair of opposingly orientedcutouts 232 to facilitate compression of the sides. Looking at theunderside of the fluid connector 128 in FIG. 13, a substantiallycylindrical guide 236 is disposed in the middle of the fluid connector128. According to another embodiment, the guide 236 is frustoconical.Centrally located within the guide 236, a fluid connector cannula 240depends from the fluid connector 128. According to one embodiment, thecannula 240 is bent at approximately 90° and extends out of the top ofthe fluid connector to connect with the tubing 136, which is omittedfrom FIG. 12 for clarity. According to one embodiment, the cannula 240is made of metal. According to another embodiment, the cannula isplastic and is integrally formed with the fluid connector 128.

Additionally, the fluid connector 128 has a two-part connector forconnecting with the base 132, including first connectors 244 (orL-shaped legs 244) and second connectors 248 (or cantilevered connectortabs 248). As described in greater detail below, once connected to thebase 132, the L-shaped legs 244 prevent axial displacement of the fluidconnector 128 relative to the base 132, and the connector tabs 248prevent rotation of the fluid connector 128 relative to the base 132.

As shown in FIGS. 14-16, the base 132 has a central conical guide 252corresponding to the guide 236 of the fluid connector 128. According toone embodiment, the base guide 252 is a septum cap 252 that maintainsthe split septum 256 (shown, for example, in FIG. 17) within the base132. Preferably, the septum 256 is made of a flexible material, such asisoprene. According to another embodiment, the guide 252 is integrallyformed with the remainder of the base 132, and the top of the guide 252is swaged over to maintain the septum 256 within the base.

Additionally, the base 132 has a plurality of horizontal lockingstructures 260 or locking channels 260 and a plurality of engagingprotrusions or vertical locking members 264. The vertical lockingmembers 264 are L-shaped and correspond to the L-shaped legs 244. Thelocking channels 260 are recessed from the top surface of the base 132and correspond to the connector tabs 248. The respective correspondenceof the locking channels 260 and the vertical locking members 264 withthe connector tabs 248 and the L-shaped legs 244 provide multiple (fourin this embodiment) different rotational orientations of the fluidconnector 128 relative to the base 132. It will be understood by oneskilled in the art that more or fewer orientations can be obtained byproviding more or fewer connecting elements without departing from thescope of the present invention. Further, it will be understood by oneskilled in the art, for example, that the fluid connector 128 can havefewer L-shaped legs 248 (for example, 1 or 2) and still provide multiplerotational orientations of the fluid connector 128 relative to the base132.

The locking channels 260 have an insertion portion 268, a hook 272, anda locking portion 276. To connect the fluid connector 128 with the base132, the patient inserts connector tabs 248 into the insertion portion268 and subsequently rotates the fluid connector 128 relative to thebase 132 until the connector tabs 248 pass the hooks 272 and snap intothe locking portions 276. During this insertion, the bottom portions ofthe L-shaped legs 244 are inserted between the vertical locking members264, and during the rotation, the bottom portions of the L-shaped legs244 slide under the cantilevered arms 284 of the vertical lockingmembers 264.

FIGS. 15 and 16 illustrate the respective interaction of the lockingchannels 260 and the vertical locking members 264 with the connectortabs 248 and the L-shaped legs 244 to lock the fluid connector 128 withthe base 132. In addition to preventing axial removal of the fluidconnector 128, as shown in FIG. 15, the vertical locking members 264also prevent rotation of the fluid connector 128 in the clockwiserotational direction as viewed from the top. In addition, as shown inFIG. 16, once the connector tabs 248 are engaged with the lockingportions 276, the locking portions 276 prevent rotation of the fluidconnector in both the clockwise and counterclockwise rotationaldirections.

To remove the fluid connector 128 from the base 132, the user squeezesthe wings in the fluid connector created by the cutouts 232. This actionmoves the connector tabs 248, which are disposed on the wings, radiallyinward, thereby disengaging the connector tabs 248 from the lockingportions 276. Next the user rotates the fluid connector in thecounterclockwise direction (i.e., opposite to the direction of theinitial connection) and lifts the fluid connector 128 axially away fromthe base 132.

As shown, for example, in FIG. 14, the base 132 also includes aplurality of detents 280 recessed from the bottom side thereof forengaging the feet 192 of the cantilevered base arms 188 describedpreviously.

Because this is an intradermal device with the patient needle 292penetrating the skin (for example, between 1-2 mm), it is important toaccommodate bunching of the skin during injection. Turning to FIGS. 17and 18, the bottom of the base 132 includes a central protrusion or cone288 from which the patient needle 292 extends, and a conical outer ring296 spaced from the central protrusion 288. This space between the outerring 296 and the cone 288 (about 1-2 mm) provides for the deformation ofthe skin at the injection site and ensures proper seating and depth ofthe needle 292. The cone 288 also acts as a depth stop. According to oneembodiment, the needle 292 is glued into the cone 288 from the proximalside (not the patient side) of the base 132 to ensure complete needlepenetration into the patient. As shown in FIG. 17, both the cone 288 andthe outer ring 296 extend beyond a central opening in the adhesive pad,with the cone 288 extending farther than the outer ring 296.Additionally, according to one embodiment, the needle 292 has a sideport 298. The side port 298 can be in addition to or instead of an endport of the needle 292.

FIG. 19 illustrates an alternative base with locking structures 304that, in contrast to the previously-described recessed locking channels260, protrude upward from the top surface of the base 300. In furthercontrast, rather than preventing rotation in both clockwise andcounterclockwise directions, the locking structures 304 only preventrotation in the counterclockwise direction when engaged with theconnector tabs 248. Otherwise, the function and operation of the base300 is substantially similar to the base 132.

FIG. 20 is a perspective view of an insertion device assembly 316 inaccordance with another embodiment of the present invention. As shown inFIGS. 20 and 21, the device 316 includes an inserter cap 320, a plunger324, a biasing member or spring 328, an inserter base 332, and theinfusion set 124 both actively and passively retained in the inserterbase 332.

The inserter cap 320, the plunger 324, and the inserter base 332 can bemanufactured using a two-piece molding process. As shown in FIGS. 22 and23, the inserter cap 320 includes plunger openings 336 for portions ofthe plunger 324 to extend therethrough and a tubing opening 340 toprovide free movement of the tubing 136. Inside of the inserter cap 320there is a cruciform 340 for retaining an upper end of the spring 328,wing guide slots 344 for guiding wings 348 of the plunger 324, and armguide slots 352 for guiding cantilevered arms 356 of the plunger 324.According to on embodiment, the inserter cap 320 snap-fits onto theinserter base 332.

FIGS. 24-27 illustrate the plunger 324. The plunger 324 includes aninternal cavity 360 with a cruciform 364 disposed in the bottom thereoffor retaining the bottom of the spring 328. Pushbuttons 368 disposed atthe free ends of the cantilevered arms 356 provide a patient interfacefor activating the inserter. As best shown in FIG. 27, each of thepushbuttons 368 includes a chamfer 372 at an external bottom portionthereof to ease movement of the pushbuttons 368 past a lip 376 (see FIG.21) of the inserter cap 320. The wings 348 have a ramp surface 380 and aguiding surface 384. As shown in FIG. 26, the bottom of the plunger 324includes a hammer portion or striking surface 388 for impacting orstriking the infusion set 124. The hammer portion 388 has a cutout 392to accommodate the tubing 136.

FIGS. 28-31 illustrate the inserter base 332. The inserter base 332includes a tubing opening 396 corresponding to the tubing opening 340 ofthe inserter cap 320, to accommodate the tubing 136. The inserter base332 also includes active and passive infusion set retainers. Flexible,cantilevered retainer arms 400 are the active retainers and flexible,cantilevered arms or tabs 404 are the passive retainers. Thecantilevered retainer arms 400 have hook ends 408 disposed at thetop-most unsupported end thereof, and, as shown in FIGS. 28-30, theretainer arms 400 also have feet 412 for engaging the infusion set 124.According to one embodiment, the arms 400 and the tabs 404 hold theinfusion set 124 spaced apart from the patient's skin. According toanother embodiment, the cannula 292 can contact the patient's skin.

When the user inwardly presses the pushbuttons 368 of the plunger 324 toclear the lip 376, the spring 328 forces the plunger 324 downward.During this downward movement, the ramp surfaces 380 and the guidingsurfaces 384 of the wings 348 outwardly displace the retainer arms 400of the inserter base 332, as shown on the right-hand side of FIGS. 31and 32. This action also disengages the feet 412 from the detents 280 inthe infusion set 124. Subsequently, but prior to the plunger 324striking the infusion set 124, the guiding surfaces 384 pass the hookends 198 of the retaining arms 400 and the retaining arms 400 return totheir initial position, as shown in FIG. 33.

Thus, in the last portion of the stroke of the plunger 324, the entireforce on the plunger 324 is from the spring 328. In other words, thereis no frictional resistance on the plunger 324 after the retaining arms400 move to their initial positions, until the striking surface 388 ofthe plunger 324 strikes the infusion set 124. The action of the plunger324 striking the infusion set 124 releases the infusion set 124 from thepassive cantilevered tabs 404 and provides the infusion set 124 withsufficient energy to drive the metal intradermal hub needle 292 into thepatient's skin. According to one embodiment, after release from theinserter base 332, the infusion set 124 travels free from the inserterbase 332 and the plunger 324. Additionally, although the insertiondevice assembly 316 is depicted with the infusion set 124, it will beunderstood by one skilled in the art that other infusion sets can beused without departing from the scope of the present invention.

According to one embodiment, the insertion device assembly 316 is asingle-use device. According to an alternative embodiment, the inserterportion of the insertion device assembly 316 is reusable.

FIG. 34 is an exploded view of an insertion device assembly 420 inaccordance with another embodiment of the present invention and FIG. 35is a cross-sectional view of the assembly 420 subsequent to activation.The assembly includes an inserter cap or button 424, a biasing member orspring 428, a plunger 432, an inserter base 436, and the infusion set124. According to one embodiment, the assembly 420 also includesresilient pads 440 to reduce the shock of the impact of the plunger 432on the infusion set 124.

As shown in FIG. 35, both the button 424 and the plunger 432 havecentral protrusions for mounting the spring 428. Additionally, theplunger 432 has a pair of cantilevered arms 444 with hooks 448 disposedat the unsupported ends thereof. The inserter base 436 includesretaining structures 452 at the top thereof for retaining the hooks 448when the plunger 432 is in the pre-activated position. Further, thebutton 424 includes an internal activating structure 456. According toone embodiment, the activating structure is a pair of cantilevered arms456 with tapered ends. According to another embodiment, the activatingstructure 456 is a hollow cylinder 456 with a tapered distal rim.

According to one embodiment, retaining arms 460 hold the infusion set124 in a single axial position relative to the base 436 that is spacedapart from the patient's skin. According to another embodiment, thecannula 292 can contact the patent's skin.

In use, the patient first removes the backing from the adhesive pad 228,primes the infusion set, and then places the assembly 420 over thedesired infusion site. When the user depresses the button 424, thetapered end of the activating structure 456 dislodges the hooks 448 fromthe retaining structures 452, and the plunger travels distally under theforce of the spring 428. Upon impacting the infusion device 124, theplunger 432 imparts momentum to the infusion set 124 and releases theinfusion set 124 from the retaining arms 460 of the inserter base 436that retain the infusion set prior to the impact of the plunger 432. Inother words, as in the other described inserters, the impact of theplunger 432 releases the infusion set 124 from the inserter. Thus, as inpreviously-described inserters, after activation, the infusion set 124is completely free of the inserter. The imparted momentum drives theneedle 292 into the patient's skin.

According to one embodiment, the button 424 includes hooks 464 thatlatch into openings 468 in the inserter base 436 to prevent the spring428 from dislodging the button 424 from the assembly 420. Additionally,once the button 424 is depressed to activate the assembly 420, the hooks464 latch into openings 472. This latching with openings 472 secures thebutton 424 to the inserter base 436 to prevent re-use of the inserter.According to another embodiment, the inserter is re-usable. Further,although the insertion device assembly 420 is depicted with the infusionset 124, it will be understood by one skilled in the art that otherinfusion sets can be used without departing from the scope of thepresent invention.

In addition to the previously-described embodiments, other features canbe employed with the inventive insertion device assemblies. For example,FIG. 36 illustrates the insertion assembly 100 of FIG. 1 with themembrane 208 already removed. In the state depicted in FIG. 36, amajority of the tubing 136 and a cannula guard tray 480 have also beenremoved from a cavity 484 in the inserter housing 118. Prior to itsremoval from the cavity 484, the tray 480 protects the cannula 292 andseparates the tubing 136 from the infusion set 124. In the embodimentshown, in FIG. 36, the adhesive pad 228 does not have an adhesivebacking, and thus, in addition to protecting the cannula 292, the tray480 protects the adhesive pad 228 by preventing contact with the tubing136. A feature, such as standoffs 488 space the tray 480 from theadhesive pad 228. According to another embodiment, the featurepreventing contact between the adhesive pad 228 and the tray 480 can beon the inserter housing 118. According to yet another embodiment, thetray 480 is connected with an adhesive backing, and by removing the tray480, the user also removes the adhesive backing from the adhesive pad228.

Although the previously-described embodiments relate to intradermalinfusion sets, the principles of the present invention are alsoapplicable to other types of infusion sets, for example, subcutaneousinfusion sets in which the patient cannula consists of a soft plasticcatheter that is inserted with the aid of a rigid metal introducerneedle.

Although only a few embodiments of the present invention have been shownand described, the present invention is not limited to the describedembodiments. Instead, it will be appreciated by those skilled in the artthat changes may be made to these embodiments without departing from theprinciples and spirit of the invention, the scope of which is defined bythe appended claims and their equivalents.

What is claimed is:
 1. An infusion set, comprising: a base having: afirst side; an opposing, second side for contacting a patient's skin; abase guide with a port extending from the first side in a firstdirection; a base cannula extending from the second side in a seconddirection for insertion into the patient's skin; an engaging protrusionextending in the first direction from the first side of the base, theengaging protrusion having a cantilevered arm; and a locking structurecomprising a slot recessed from the first side of the base; and a septumdisposed within a fluid path between the port and the base cannula; anda fluid connector for connection with an external pump, whereinsubsequent to engagement between the fluid connector and the base, thefluid connector is rotatable relative to the base in a first rotationaldirection to lock the fluid connector to the base, the fluid connectorcomprising: a connector cannula for insertion through the port and theseptum when the fluid connector is connected with the base; an ofL-shaped leg configured to rotatably engage the cantilevered arm duringlocking of the fluid connector to the base, to prevent displacement ofthe fluid connector in the first direction relative to the base and,once the fluid connector is locked to the base, prevent rotation of thefluid connector in the first rotational direction relative to the base;a cantilevered tab configured to engage the locking structure, whereinupon locking the fluid connector to the base, the interaction of thelocking structure and the cantilevered tab prevents rotation of thefluid connector in a second rotational direction opposite to the firstrotational direction but permit displacement of the fluid connector inthe first direction relative to the base.
 2. The infusion set accordingto claim 1, wherein upon locking the fluid connector to the base, theinteraction of the locking structure and the cantilevered tab ve to thebase.
 3. The infusion set according to claim 1, wherein the recessedslot comprises an insertion portion, a hook, and a locking portion,wherein displacing the cantilevered tab from the insertion portion, pastthe hook, and into the locking portion locks the fluid connector to thebase and prevents rotation of the of the fluid connector in the firstand second rotational directions relative to the base.
 4. The infusionset according to claim 1, wherein the engaging protrusions is L-shaped.5. The infusion set according to claim 1, further comprising an adhesivepad disposed on the second side for adhering the infusion set to thepatient's skin, the adhesive pad having a central opening therein;wherein the base further comprises: a first depending structureprotruding from the second side of the base in the second directionbeyond a patient surface of the adhesive pad and through the centralopening of the adhesive pad; and a second depending structure protrudingfrom the second side of the base in the second direction through thecentral opening of the adhesive pad further beyond the patient surfaceof the adhesive pad than the first depending structure, the seconddepending structure being radially spaced from the first dependingstructure, the base cannula extending from the second dependingstructure.
 6. The infusion set according to claim 1, wherein the basecannula comprises a rigid cannula.
 7. The infusion set according toclaim 1, wherein the base cannula extends substantially perpendicularlyfrom the second side of the base.
 8. The infusion set according to claim1, wherein the fluid connector comprises has central portion, a wingportion, and a cutout that permits displacement of the wing portionrelative to the central portion; wherein the cantilevered tab isdisposed on the wing portion, and displacement of the wing portionrelative to the central portion disengages the cantilevered tab from thelocking structure.
 9. The infusion set according to claim 3, wherein thefluid connector comprises has central portion, a wing portion, and acutout that permits displacement of the wing portion relative to thecentral portion; wherein the cantilevered tab is disposed on the wingportion, and displacement of the wing portion relative to the centralportion disengages the cantilevered tab from the locking portion of therecessed slot.
 10. The infusion set according to claim 1, wherein thefluid connector is lockable to the base in a plurality of discreterotational orientations.